Power-control system



DCC 3l, v1929. A. H. NEULAND 1,741,428

POWER CONTROL SYSTEM Origlnal Filed June 15. 1923 2 Sheets-Sheetl wwwATTORN EYS Dec. 3l, '1929. A. H. NEULAND 1,741,428

POWER CONTROL SYSTEM Origlnal Filed June 1.5. 1925 2 Sheets-Sheet 2ATTORNEYS Patented Dec. 3l,

PATENT or-FICE ALFONS H. NEUL'AND, OF IRVINGTON, NEW JERSEYrPOWER-CONTIROLl SYSTEM Application led .Tune 15, 1923, Serial No.f-645,519. Renewed October 23, 1929.

My invention relates to electromagnetic systems and is particularlyintended to change the speed and torque ratios between a prime' mover oran element rotating kat a` given speed andan element orshaft the speed4and torque of which is to be changed and cone. trolled with relationofthe prime mover 4or driving element.

Une' object of my inventionis to provide for an apparatus of lightweight and high power, particularly when applied to motor vehiclesin-connection'with combustion engine's. Another object is to obtain adouble speed range of the driven element, one below the driverv speedwith correspondingly increased torque and the other range above the pdriver speed. Another object is to obtain a suiciently powerful reversetorque ywithout resorting to mechanical gearing. Another 26 Object is tohave the apparatus perform a` number. of auxiliary functions desirablethe operation of a motor vehicle such as chargmg the battery, ,startingthe engine,

. electric braking, etc. Another object of my invention isV to provide asystem capable of f developing a very powerful intermittent torque atone operating speed and at another speed to absorb or carry theentireengine torque for prolonged eriods easily and with- 30 outoverheating. St'll other objects and advantages of my invention willappear from the following specification invwhi'ch I have described mycontrol system as adapted to a motor vehicle although it is to beunderstood that this system may be employed for various other purposessuch as hoists, elevators, railway cars and the like.

Application of electrical transmission and control systeins toautomobiles has hereto- 40 fore been diiiicult due to the considerableadditional weight of the devices resulting partly from the controlmethods. employed such as weakening the field strength or shifting thebrushes, in either of which cases the torque or torque reaction islessened.

My invention overcomes these difficulties in that I maintain a strongmagnetic field and a quadraturel relation between the currents in thedynamo windings and the field. In addition I transfer only a portion ofthe engine mobile.

torque directly to the driven element while another portion of theengine torque Ais transformed into electrical energy and made toincrease the speed of the driven elementbeyond that of the engine, thehigher speed of the driven element is then'reduced by gearing orpreferably taken care of by a greater reduction ratio in the rear axleof the auto- Bythis latter` means a substantial saving in the weight iseffected. e0

My system comprises three major parts, the field or drivingv elementsecured to the enginevshaft, an armature or driven element facing thefield poles on one side and a stator or dynamo element facing the fieldpoles on the other side, so that a common magnetic fiux traverses 4theelements. The three windings on these elements are connected in seriesvto form the main circuit and the principal functions of the system areeffected; I, by 70 varying the number of stator turns in the circuit,the stator potential addingv to the armature potential and causingthe-armature to rotate faster than the field; II, by reversing a portionof the stator winding with respect to the armature, in which instancethe armature potential overcomes the stator potential,.reverses thestator current, causes the armature to rotatel'slower than the vfieldande to produce a torque exceeding the applied so torque; III, byreversing the armature winding, causing the stator potential tooverpower the armature potential thereby reversing the current in thearmature and causing it to rotate in a reverse direction tothe engine;IV, by reversing the armature and stator windings with respect to thefield when startingthe engine. In short, broadly speak ing, the systemcomprises the 4rotation of a primary or driving field element with acom- 9o mon magnetic iux emanating therefrom and producing twoindependent voltages in two induced windings forming an electric circuitin which the field winding'is included, and means forchanging themagnitude or,v direc-` tion or both of one voltage with respect to theother and to the field, While maintaining electrical quadrature betweenfield and induce'd windings, the two inducednwindings .being arranged inthe magnetic circuit so that within the stationary casing and in close`prorimity to the stator winding and the brush ea s. My invention alsocomprehends various features of electrical arrangement and mechanicalconstruction, details and arrangement of parts, as will hereinafter morefully appear. I shall now describe the illustrated embodiment of myinvention and shall thereafter point out my invention in claims.

Fig; 1 is a partial longitudinal section and a partial side elevationoit a control system embodying my invention;

Fig. 2 is a segment of a transverse section, showing the magneticstructure and particularly the construction of the eld poles and4 linkstying them to one another; y

Fig. 3 is a fragment of the field poles illustrating the manner in whichthe support-ing rods tie the links with the pole pieces;

Fig. 4 is a diagram of the electric circuits including the controllercontacts by lmeans of which connections are made corresponding to thevarious functions;

Fig. 5 is a representation` of the relative strength, positionanddirection of the currents in the three elements correspondingwith'the various controller positions in Figure 4;

Fig. 6 is a diagrammatic representation of the field commutator with itsmain and auxiliary brushes and a simplifled representation oftheelectric circuits connected thereto; l

Fig. 7 shows how the ends of the stator coils are connected to formgroups and their leads for one phase;

Fig. 8 is a partial outline of a' motor vvehicle showing particularlythe' high worm gear reduction at the rear axle.

The control system which I have selected for illustration in thedrawings is adapted to automobilespropelled by an internal combustionengine 1, in that the driving or iield element 2 serves as the -flywheel, and is rigidly secured to the crank shaft 3. The driven elementorarmature 4 is connected to the propeller-shaft 5 which is carried at oneend by the field spider 6 through the ball bearing 7. The propeller ordrive shaft is supported near its other end by the bearing 8,

which in turn, is-mounted in a bearing 'seat of the stationary bracket9; the bracket being secured to the housing 10, which carries the statoror dynamo element 411 built up of laminations having slots 12 on theirinner circumference in which Athe distributing winding 13, is embedded.-The field element 2, is provided with eight pole pieces 14, each ofwhich carries a field coil 15. The centrifugal forces acting on thefield poles is very great when the field element rotates rapidly; and inorder to withstand these forces and in order to insure rigidity while-t-he field member acts as a fly wheel for the one side and into anon-magnetic tie ring 21 on the other side. This insures a proper radialalignment of the field poles.

The armature 4 includes a winding 22 embedded in the slots 23 andconnected to the commutator 24 which is provided withan in ternal face.

Securedto the field element is the spider 25 which is carried by thesleeve or tubing 26. This tubing in turn is rotatively supported bythebearing 27 in the armature spider 28 at one end and at the other end bythe bearing 29. This construction makes for greatrigidity and preventsdistortion of the air glaps under severe operating conditions.-

T is spider `25 carries the armature brushes 30, thefive slip rings 31and the field commutator 32. Allthesc rotate with the field and togetherAwith the stationary polyphase field brushes 33, wiping the com mutator32 permit the windings of the three elements to be conductivelyconnected in series'relation with each other.

The connections between the windings are made'by means of the contactfingers 34 pressing upon the controller drum 35 which erating positionsshown in Figure 4 by 'means of the connectin rod 36, Figure 8, engagingthe ldrum gear 3 and conveniently arranged to be actuated by thecontrolling lever 38 near the steering wheel.

In Figure 4 I have shown the contacts on the controller drum surface andon the left side. indicated the functions which will be obtained fromthe controller in the various positions. Figure 5 at the rightrepresents the relative strength, positionand direction of the currentsin the stator, field and armature elements for each of the positions onthe controller.

Referring to Figures 4, 6 and 7 it is seen that the stator is providedwith a polyphase winding and preferably comprises three phases, A, B, C.The number and spacing of the stationary brushes vwiping the 'fieldcommutator must correspond to thenumber of phases comprising thestatorwinding and have the same spacing or its equivalenti.l Each phaseis furthermore divided into a number of groups, in the present instancethree groups being used providedwith the leads a, b, c, d. These groupsare so arranged With respect to each other and with respect to the fieldbrushes to which they are connected by the leads a, b, a, d, that whenthe potential in a given group or phase has decreased to zero theparticularv brush 33 to which such phase or group isconnected, 'Will' atthat moment leave the Wide effective segment on the field conimutator.

Referring to Figure 4, the fifthv step, in which the entire statorWinding is included and the connections are such that the currents inboth the stator and armature are in a forward directiom'as appears fromFigure 5. Current from the armature 4 flows to the finger e, the controlcontact f, finger g', field coil 15, segment i of commutator 44, brushy',

finger lc to contact l, finger m, coils a, b, c, d, finger n, contact o,Wire p, contact g, finger r coils dd, cc, bb, aa, finger s, contact t,finger u, brush v, segment lw of commutator 44, then to'finger contacty, finger z, and through armature 4to complete the circuit; i Y

In this stage, the prime mover transfers part of its energy or torquedirectly to the load or propeller shaft. The balance of the prime moverenergy is converted into electrical energy in the dynamoelement orstator and fed. into the armature, to increase its speed. This stagewill'drive the armature at vthe highest speed, and assuming roughly thatthere are twice as many turns i series in the stator winding as thereare in tfle armature, the speed of the armature will exceed that of4 thefield element three times because with the armature at rest the rotationof the field against it will induce a certain potential therein and therotation of the field element with relation to the stator Winding willgenerate therein a potential twice that in the armature making the totalpotential in the circuit three times that in the-armature or 300%.,Inasmuch as a 100% potential in the circuit will make the armaturerotate at nearly the' speed of the engine or practicallyy 100% itfollows that the armature will turn three times faster with a potentialthree times higher.

Thehigh speed of the driven armature and the propeller shaft 39connected thereto is reduced at the rear aXle by means of the wormgearing 40. -It is tobe-no'ted that While I prefer to use a higherreduction ratio in the rear axle than found inpresent standardautomobiles, I amable, on account of the ydouble speed range of themachine to select a reduction ratio that Willproduce a greater car speedwith a` given engine speed; for iiistance: One standard make ofautomobile will travel 20 miles per hour with the engine turning 900 R.P. M. and rear axle havngfa reduction 41/2 1. With my system or; thefifth step with the engine turning at 900 R. P. M.y and the reductionratio of 9:1, the ar speed Would be 30 miles per hour, thus ef- (fectinga. saving in fuel and oil. In this connection it should also be notedthat the engine torque is absorbed,v partly by the armature due to thedirect transfer of the torque and partly by the stator Winding. It isthe last named torque component that is converted into electrical energyand transferred to the armature in the form of increased speed. i

In the-fourth step the armature and field connections remain the same asin the fifth step except'that one group in each phase of the statorWinding is left out of circuit, this being the group c d, and it Will beseen that the magneto motive forces in the remaining groups a, b, c,have not changed their center with respect to the field brushes. In thisstep the speed of the armature is reduced with respect to that ofthefield. In this controller position', current from the'armature 4 flowsto the finger e, controller contact f, finger g, field coil 15, segmenti, of commutator L44, brush j, finger lc, contact l, nger m, throughcoils a, b, finger ee, contact yf, Wire p, contact gg,

finger hh, coils bb, aa, finger s, contact t, finger u, brush fv,segment Iw, finger Contact y,

finger z, and backto the armature 4 to complete the circuit.

Inl this stage, a larger portion of energy' and torque is directlytransferred to the armature or load, the balance being transformed intoelectrical energy in the dynamo element and fed into the armature tosupply the differential speed. v In the third step the number of statorturns in series is still' further reduced, the group c d alone beingused in ea'ch phase. This further reduces the armature speed withrespect to the driver and again it should be noted that the force'center has not changed. In this step the bulk of the engine energy isdirectly transferred to the load, and only a minor por'- tion'isconverted -into electrical energy and fed to the `armature to amplifyits speed. In this step, controller position 3, current from thearmature 4 flows to finger e,controller con- 1 tact f; finger lg, fieldcoil 15, segment i of commutator'44, brush j, finger c, contact tz',finger ee, coils cd, finger n, contact jy', Wire p, contact cc, finger7', coils dd, ce, finger hh, contact ZZ, finger u, brush o, segment w,finger contact y, finger z, and back to armature 4 to complete thecircuit.

The second step comprises straight drive, the stator winding beingentirely left out of circuit and the field brushes being closed uponthemselves so that the armature and field operate as a clutch the speedof the one being nearly that of the other. In this step, current fiowsfrom the armature 4 to finger c, con? troller contact f, finger g, fieldcoil 15, segf i tion ratio upon the saving in the weight andl size ofthe apparatus for the reason that with a 9 :1 rear axle ratio assumedabove a given engine torque will develop twice the torque at the rearwheels compared with present practice using a 41/2 :1 ratio, orinversely for a given torque required at the rear wheels the drive shaftor driven element will only have to supply one half the'torque otherwiseneeded; consequently the transmission dievice can be of smallerproportions and lighter weight.

In the first forward step the armature and lfield connections are thesame as above and one group per phase of the stator windings is includedin the circuit but in a reverse rela-' tion to the armature, as shown inFigure 5, the armature potent1al predomlnating and causing currents inthe stator winding to flow in the reverse ldirection. In this step,current from the armature'4 flows to the finger c, controller contact f,finger g, field coil 15, segment z' of lcommutator 44, brush j, fingerla, contact o0, finger ee, stator coil b in reverse direction, fingerpp, contact gg, wire p, contact M", finger ss, coil'bb, finger hh,contact tt, finger u, brush e, segment'w, finger contact y, finger a,back to armature 4 to complete the circuit.

In thisstage, the torque supplied to the load or propeller shaft` isamplified or boosted. The prime mover transfers its full torque to theload` at a reduced speed or speed difference. Due to this speeddifference, the dierential electricaL/energy thereby produced isconverted into mechanical energy .f

by means of a dynamo element 13 and return tothe prime mover. Thearmature speed is thereby considerably reduced, and the energyrepresented by the slip'is consumed in the stator and made to produce atorque on the fieldelement so that the field element while exertingapowerful torque on the armature receives only a part o f that torquefrom the prime mover and another part from the stator element and asaresult the torque devel oped by the driven element exceeds that of theprime mover. It should be noted thatfthe flow of energy due to the speeddierence, be-

tween the prime mover and the load, that is,y

the flow of differential energy -between the dynamo windings 13 and 22reverses. In the first step or stage, the differential energy fiows.from the winding 22 of the load armatugre 4 to the stator or dynamowinding 13; inthe third and other stages, the differential energy flowsfrom the dynamo element 13. to the winding 22 of the load armature, sothat in the first stage the dynamo winding 13 operates as a motor and inthe third, fourth and fifth stages, as a generator. The armature winding22', however, operates as a generator in the first and second stages,and as a motor -in the third, fourth and fifth stages.

.When the controller is in the position indicated as Reverse preferablythe entire sta- ,tor winding is in the lcircuit but the connections tothe .armaturebrushes are reversed. In this step,U current from armature4 now fiows to finger z, controller Contact 50, wire 51, contact j",finger g, field coil 15', segment z' o f commutator 44, brush j, finger7c, contact 52, finger m, stator coils a, b, c, (l, finger n, contact53, wire p, contact 54, finger 7^, stator coils (Zd, cc, bb, cm, fingers, contact 55, finger u, brush yv, segment fw, finger as', contact '56,finger e, back to armature 4 to complete the` circuit. VThe stator turnsand potential eX- ceed that of the armature and will overpower andreverse the currentin the armature as indicatedin Figure 5. Under thesecondi# tions the field element although rotating in one direction willproduce a powerful torque 4on the armature in the direction opposed toits own, it being apparent that the armature by such reverse rotationassists the forward rotation of the field elementusing it as a fulcrum,the field element in turn being retarde ed b v the stator currents. t

The Start position onthe controller will make connections from thebattery 41 to the armature and a circuit in multiple to the armature isalso established including the field and the stator winding in serieswith each other. In this position, current fiows from the battery 41 to'finger 57, contact 58, to a divided path. Part of the current flows tofinger s, armature 4, finger e, Contact f, wire 5 1, contact 58, back tothe battery 41. The other part of the current flows from ,contact 58, tofinger segment 'w' of commutator 44, brush e, finger u, contact tt,finger hh, stator coil. bb, finger ss, Contact 59, wire p, contact 60,finger pp, stator coil b, finger ce, contact 00, finger 7c, brush y',segment #i of commutator 44, field 15, finger y, contact f, wire 51,contact 58, and finger 59, back to the battery 41 to complete the secondcircuit. VFigure 5 shows that both armature and sta# tor currents varereversed causing the field element to rotate forward and to start theengine. The use of both windings for this purpose produces a powerfultorque and helps to overcome the engine compression;as the field elementgathers speed the counterpotential in the stator winding weakensthefield current automatically and enables the field element to attain avigorous starting speed with a :battery of moderate size andvoltage.This feature is not claimed herein but is claimed in `my copendingapplication Serial No. 162,788, filed January 22, 1927.

My invention also provides electro-magnetic retardation for the vehiclewhen coasting or when descending a grade. The con--` nections for thispurpose are established with the controller in the Brake position withthe stator winding included andthe yarmature leads reversedf In thiscontroller position, current from the armature 4 flows to the finger tothe resistance 42, finger 61, con-- tact 62, wire 51, contact f, fingerg, field coil 15, segment z' of commutator 44, brush j, fin- 'er]c,Contact 00, finger ec, stator coils c, d,

nger n, contact 63, wire p, contact 64, finger 1', stator coils dd, ce,finger hh, Contact tt, finger u, brush o, segment 'w of commutator 44,finger contact 64, finger e, back to the armature 4 to complete thecircuit. In addition the resistance 42 is in circuit serving to consumea portion of the energy generated.

vIt is seen that the armature drags the field element, the latter beingretarded bythe stator current, and. that the braking can be regulatedvby adjusting the resistance 42.

The remaining position of the controller is at Off. The armature leadsand the stator winding are reversed. With the leads so connected and thevehicle at rest, rotation of the driver or field Yelement cannotgenerate any current. These connections further serve the purpose ofstarting the engine by the coasting vehicle, sliould theengine havestopped asr isv often the case. Thus current flows from the armature 4to finger z, contact 65, wire 51, conl tact f, nger g, field coil 15,segment d of commutator 44, brush y', finger k, contact` 00, finger ee,stator coil b, finger pp, contact gq, wire p, Contact rag/finger ss,stator coil bb, finger hlt, contact tt, finger u, brush o, segment w ofcommutator44, finger Contact 64, finger e, back to the armature 4 tocomplete the circuit. The inclusion of the stator winding 'is importantin that it supplies a part of the starting torque and so limits the rushof current in the circuit and greatly relieves Y the strains in the rearaxle gearing.

This device is also capable of charging the battery7 41 and connectionismade by means of the 'automatic switch 43 which closes the `batterycircuit when the generator `voltage becomes sufficiently high.Inspection of Figure -4 shows that on steps` second' and-third thebattery is connected directly across theJ armature while Aonsteps'fourth and fifth one battery lead is connected to the neutralpoint of the stator winding and the other tofthe field lead. On'firststep one'lbat'tery lead L again connects to therstator neutral and theother to the field.commutator lead. f

Thelast contact finger 34 at the extreme'` left ofFigure '4 makesconnection' with the corresponding contacts 'on lthe, controllerneetions and to open thegfield shortafter the connections for the newstep have been established. This effectively quenches the sparkingat'the controller contacts. n

Int Figure 7 I have shown the ends lof the stator conductors for a fourpole model and. in a simple way, the manner in which the ends of theconductors are connected to give the required grouping, showing also theleads from the groups. For the sake of greater clarity I have shown theconnections for one phase only, and have represented one coil of 'saidphase, the other coils of the phase being wound and connectedprogressively in the manner shown, as will be well understood. Thecorrect grouping of the winding is im-v portant to insure goodcommutation at the field commutator. It is seen that when the leadsc d,a o Orla al' are actively connected, the center of the statormagnetomotive force will coincide with and be in the postion indicatedby the dotted line. This corresponds to the steps 3, 4, -`5 and Reverserespectively. For these steps the stator winding is connected in aforward direction so that the field distortion will be in the samedirection for the steps mentioned insuring good commutation with thesame setting of the brushes 33. In stepfirst, however, a portion ofthestator winding is reversed and the field distortion therefore takesplace in the opposite direction; to compensate for this, I` 'shift thecenter of the In Figure 6 I have shown the particular construction ofthe field commutator Icomprising the wide active segments 44 and theintermediate segments 45 serving to separate and insulate the activesegments 44 from each other. There must be one active and oneintermediate section-per pole, the commutator illustrated, being adapted.for four poles.v

This commutator is wiped kb the 'main brushes 33 of which there must v eat least as i many as there are phases in the stator`winding; similarlythey must be spaced from each other the same number of electrical spacedegrees as the phases of the stator winding.

Preferably the main brushes are of suchv width that in a three phasemachine two brushes Awill make full contact with'the active segments.

The described arrangement will give good commutation with moderate voltaes. For

higher voltages and in order still rther to improvethe commutation, thefield commutator 1s provided with auxiliary brushes 46',

which are much narrower and thinner than the main brushes 33 and4respectively connected to the latter through the resistanees 47. Theposition of the auxiliary brushes on the commutator is -suchthat themain brushes leave the active segments ust before the auf;- iliarybrushes to the end that any small amount of current still at the brushes'at that moment will be forced to traverse the resistance 47 before thefinal break between the brushes and active segments occurs.

It is obvious that various modifications may be made in the constructionshown in the drawings and above particularly described Within theprinciple and scope of my invention.-

I claim:

1. The method of transmitting power from a rotating field member that isoperated by a prime mover at a 'predetermined torque to a drivenarmature member inductively related to the field member in one stage ata torquey exceeding that of the prime mover and in another stage attorque substantially equalling that of the prime mover, saidv methodconsisting in the first stage in feeding the slip energy to a stationaryWinding inductively related to the field member to cause the stationarywinding to exert an added torque upon the lfield member and through itupon the armature, and in the second stage increasing the armature speedto substantially that of the field member by leaving the stationarywinding out of the armature circuit.

2. The methodof transmitting power. from a driving rotative memberreceiving energy from an external source to a driven rotative memberconsisting in inducing a voltage in an induced Winding on the drivenmember by the'rotation of a field member in inductive relation thereto,simultaneously inducing an independent voltage in a second inducedWinding by the rotation of the field member rin inductive relationthereto, supplying the voltage in I the second winding v.to the firstWinding, and varying the turns of the second Winding to vary the voltageinduced therein. 3. An electro-magnetic power transmission' devicecomprising a driving rotative field member including7 a field Winding, astator adjacent the field member on one side thereof and including acore arranged to conduct the field flux and a polyphase Windinginduetively related to the field winding, a driven rotative armatureopposing the field member on the other side thereof and including a corecompleting the flu ypath and ajwinding inductively relatedto the field'winding, means for connecting the three windings inseries with eachother, and means for varying the turns in series of the-severalphases'jof theY stator winding; l v I 4. An electro-magnetic powertransmission device comprising a driving rotative field member includinga field Winding, a stator adjacent theeld'mmberon one side thereofandincluding'a. core arranged t0 .conduct th ly related to the fieldWindino' field flux and a polyphase Winding inductivea driven rota.-tive armature opposing lthe the other side thereof and including a corecompleting the flux path and a Winding inductively related to the fieldwinding, means for connecting the three windings in series.

with each other, and means for including a hield member on portion ofeach phase of the statorfwinding into the circuit in a reversedirection'with respect to the armature Winding.

5. An electro-magnetic power transmission device comprising a drivingrotative field member including a field winding, a stator adjacent thefield member on one side thereof and includingy a core arranged toconduct the field flux and a polyphase winding inductively related tothe field Winding, a driven rotative armature opposing the field'memberon theother side thereof and including a core completing the fiuX pathand a Winding in- 'side and including a core and a polyphase Windinginductively related to the field member, a driven rotativearmaturefacing'f the other side of the field member and including a coreand a commutator and a winding connected to the commutator andinductively related to the field member, stationary polyphase s'pacedbrushes wiping the field commutator, direct current brushes carried bythe field member and wiping the armature commutator, and controllingmeans arranged in control of the circuit connections and opera' 'tivefor one step to connect a relatively large number ofthe turns of eachphase of lthe stator Windinov to the respective' polyphase brushes andar' another step to connect .a lesser numberfof turns of each phase ofthe stator .Winding to the respective polyphase brushes, saidcontrolling means including `means for making connection between thefield coils and the field commutator to form with the stator winding'aseries circuit for each step'. A

` 7. An'electro-magneticpower transmission device comprising a drivingrotative field member including field coils and a .commutator, a statorfacing the field member on one side and-including a core and a olyphaseWinding inductively. related'to the eld member, aydriven rotativearmature facing the other side'of the field member'andincluding a coreand a commutator` anda winding con nected-to the commutator andinductively relatedto th'e field member, stationary poly- 'phase 'spacedbrushes wiping `the field com-l l erative for one step tov connect arelatively large number of the turns'of each phase of the stator windingto the respective polyphase.

brushes, for another step to connect a lesser number of turns of eachphase of the stator Winding to tlie respective polyphase brushes, andfor another step to connect a relatively small number of turnsof eachphase of the stator Winding in a reverse diiection to the respectivepolyphaseK brushes, said lcontrolling means including means for makingconnection between the field coils and the field commutator to form withthe stator' winding a series circuit for each step.

8. An electro-magnetic power transmission device comprising a drivingrotative field member including field coils and a commutator, a statorfacing the field memberon one side and including a core and a polyphasewinding inductively related to the field member, a driven rotativearmature facing the .other side of the field member and including a coreand a commutator and a winding connected to the commutator andinductively related to,the field member, a stationary polyphase kspacedbrushes wiping the field commutator, direct current brushes. carried bythe field member and wiping the armature commutator, and controllingmeans arranged in control, ofthe circuit connections and operative forone step to connect each phase of the stator winding to the respectivepolyphase brushes and to connect the direct currentI brushes with thefield and field commutator leads, whereby the field coils,\statorwinding and armature winding are connected in series, and for anotherstep to reverse the connections of thedirec't-current brushes into thecircuit.

9.v An electro-magnetic power transmission device comprising a` drivingrotative field member including field coil's'and a commutator, a statorfacing the field member onone l f ,Y a core and a commutator and awinding conside and including` a core and a polyphase Windinginductively related to the field member, a driven rotativevarmaturefacing the other side ofthe field member and including nected to thecommutator and inductively relatedto the field member, stationarypolyphase spaced brushes wiping the field commutator, direct currentbrushes carried by the l field member and wiping the armaturecommutator, and controlling meansA arranged in control of the circuitconnections and operative for one step tol connect each phase o f thestator windingfto the respective polyphase brushes and. toY connect thedirect current brushes with the field and field commutator-- leads,wherebythe field coils, stator winding and armature winding areconnected in series,

and for another step to reverse'the connections of the stator windingand of the direct current brushes.

VlOfAn electric-magnetic power transmis- Ysion device comprising a.`drivingl rotative field member including field coils and a commutator, astator facingthe field member on one side and including a core and apolyphase Winding inductively related to the field member, av drivenrotative armature facing the other side of the field member landincluding a core and a commutator and a winding connected to thecommutator and inductively re-` lated ltothepfield member, stationarypolyphase spaced brushes wiping the field commutator, direct "currentbrushes carried by the field member and wiping the arma-ture commutator,and controlling means arranged in control of the circuit connectionsland operative, for one step to connect a relatively large number of theturns of each phase ofthe stator winding to the respective polyph-asebrushes and to connect the direct current brushes with the field andHeld commutator leads, and for another step to connect a lesser numberof turns of each phase of the stator winding to the respective polyphasebrushes and to reverse the connections of the direct current brushesinto the circuit.` I

vlll. An electro-magnetic power transmis- 'sion device comprising adriving rotative field member, a stator including a polyphase windinginductively related to the field member, a driven rotative armatureincluding a`winding inductively related to the field member, each phaseof the polyphase winding being divided into a numberof groups and havingleads from the'opposite endsyof each group and one group being arrangedpartially on each end of the phase winding, whereby the center of thestator magneto motive force is unchanged for various of the leadconnections and is properly shifted when two of the leads areconnected-in a reverse direction, and means including a commutator andpolyphase spaced brushes for variously .connecting thegioi'gps of eachphase ofthe stator winding in series with the armature winding and'coilsof the field member.v

12. The means for operating a'load shaft at speeds over and under thatof the power shaft which comprises'an armature for one of the'shafts, aeld element including series field vcoils for the other s haft, a seconddynamo stantially 'the entire current from the armature through the,lfield coilswhen the load shaft underspe'ds vthelpovi-s/haft and for'.

passing substantially .theientifre currentfrom the second dynamo elementthrough the field bcoils when the load shaft overspeeds .the

:power shaft and means for 'f'changingthe speed of the load shaft fromone condition to the other.

13. The method of energizing the field of u clutch dynamo interposedbetween a power source and a load for operation of the load at speedsybelow and above they power source which consists in energizingr saidfield from l the armature of the clutch dynamo when the load operates ata speed below thatv of the power source and energizingl said field froman auxiliary dynamo element receiving energy from the power source whent-he loud operates at speeds above the power source.

In witness whereof, I hereunto subscribe my signature.

ALFONS H. NEULAND.

